A5100653704- Magnetic confinement fusion research
- Particle accelerators and beam dynamics
- Superconducting Materials and Applications
- Gyrotron and Vacuum Electronics Research
- Advanced Fiber Laser Technologies
- Ionosphere and magnetosphere dynamics
- Fusion materials and technologies
- Laser-Plasma Interactions and Diagnostics
- Photorefractive and Nonlinear Optics
- Solid State Laser Technologies
- Microwave Engineering and Waveguides
- Photonic Crystal and Fiber Optics
- Advanced X-ray Imaging Techniques
- Particle Accelerators and Free-Electron Lasers
- Photonic and Optical Devices
- Advanced Fiber Optic Sensors
- Digital Holography and Microscopy
- Physics of Superconductivity and Magnetism
- Solar and Space Plasma Dynamics
- Pulsed Power Technology Applications
- Plasma Diagnostics and Applications
- Laser-Matter Interactions and Applications
- Optical Coatings and Gratings
- Laser Design and Applications
- Orbital Angular Momentum in Optics
Huazhong University of Science and Technology
2015-2024
State Key Laboratory of Advanced Electromagnetic Engineering and Technology
2022
Beijing University of Technology
2012
Shanghai Institute of Optics and Fine Mechanics
1987-2008
Chinese Academy of Sciences
1997-2007
University of Science and Technology of China
2001-2007
Academia Sinica
1990-1998
The J-TEXT tokamak has been operated for ten years since its first plasma obtained at the end of 2007. diagnostics development and main modulation systems, i.e. resonant magnetic perturbation (RMP) systems massive gas injection (MGI) will be introduced in this paper. Supported by these efforts, contributed to research on several topics, especially RMP physics disruption mitigation. Both experimental theoretical show that could lock, suppress or excite tearing modes, depending amplitude,...
Abstract The J-TEXT capability is enhanced compared to two years ago with several upgrades of its diagnostics and the increase electron cyclotron resonance heating (ECRH) power 1 MW. With application wave (ECW), ECW assisted plasma startup achieved; tearing mode suppressed; toroidal injection 300 kW drives around 24 kA current; fast electrons are generated injected runaway current conversion efficiency increases ECRH power. coupling between 2/1 3/1 modes extensively studied. coupled usually...
The joint TEXT (J-TEXT) tokamak, formerly TEXT/TEXT-U operated by the University of Texas at Austin in USA, has been re-built up Huazhong Science and Technology China. machine run for two experimental campaigns since 2007. Discharges with plasma current beyond 200 kA duration 300 ms have obtained. At present all sub-systems, such as poloidal field (PF) toroidal (TF) power supplies, vacuum system, diagnostics systems etc, are successfully integrated into routine operation. position can be...
A novel acousto-optic switch operation by a simple laser-diode pumped acousto-optic, Q-switched, ytterbium-doped, double-clad fiber laser is reported. Stable compressed Q-switched sub-40 ns pulses with beam quality factor (M(2)=2) are achieved at the repetition rate of 1-50 kHz. ~20 microJ pulse energy and 35 width obtained 50 Finally, reasonable explanation presented.
We put forward the idea of implementing a confocal setup to suppress large sidelobes spreading all through field outside central core. They are produced when an apodization film is imposed on ordinary lens. Furthermore, this avoids imaging quality degradation caused by nonaxial points and non-Gaussian-plane points. Also configuration for achieving three-dimensional superresolution depicted discussed.
A 1 MW electron cyclotron resonance heating system has been designed and developed for J-TEXT tokamak not only to enhance the total power but also provide another possible way control plasma parameters. The is composed of two gyrotrons, both with an output 500 kW wave power. development progress elaborated discussed. commissioning tests gyrotrons were implemented, each gyrotron realized its standard successfully. With assistance this system, a variety experiments have carried out on J-TEXT,...
We present the experimental result of electrocontrolled two-beam coupling in photorefractive SBN:Ce crystals. The direction and gain can be predetermined by an externally applied dc electric field, shows a bistable behavior. A theoretical explanation is also given.
A wide-viewing-angle visible light imaging system (VLIS) was mounted on the Joint Texas Experimental Tokamak (J-TEXT) to monitor discharge process. It is proposed that by using film data recorded plasma vertical displacement can be estimated. In this paper installation and operation of VLIS are presented in detailed. The estimated result further compared with measured an array magnetic pickup coils. Their consistency verifies estimation J-TEXT promising.
Electrode biasing experiments are carried out on the KT-5C tokamak to investigate effects of radial electric field E/sub r/ turbulence. A modestly enhanced gradient layer is formed at plasma edge by electrode biasing. In layer, reductions in fluctuation amplitude, correlation length and turbulent particle flux observed. These results support theoretical models turbulence suppression decorrelation due E /spl times/ B flow shear.
The limiter target electrostatic measurement system including grounding current sensors and Langmuir probes have been newly developed for the of area on Joint-Texas Experimental tokamak (J-TEXT). Current fixed between graphite limiters vacuum vessel walls are used to measure currents wall. Simultaneously, a rectangular poloidal array containing 54 is embedded in tiles more localized measurement. Based this system, effect both plasma's inherent behavior, plasma motion 2/1 tearing mode,...
Two types of fast protection units are designed and established to ensure the safe operation electron cyclotron resonance heating (ECRH) system on Joint Texas Experimental Tokamak (J-TEXT). One is overvoltage overcurrent unit; other arc unit. All them used send signals control unit for switching off high-voltage power supplies gyrotron when there a fault. The circuits based two tested. response time circuit less than 900 ns, 1.2 μs. test results show that these can fulfill requirements ECRH J-TEXT.
Abstract In order to broaden the range of plasma parameters and provide experimental conditions for physical research into high-performance plasma, development electron cyclotron resonance heating (ECRH) system J-TEXT tokamak was initiated in 2017. For first stage, ECRH operated successfully with one 105 GHz/500 kW/1 s gyrotron 2019. More than 400 kW (EC) wave power has been injected successfully, raising core temperature 1.5 keV. 2022, another completed commissioning tests which signifies...
Compatible operation of steady state mode and pulse is realized in the KT-5D device. New power supplies with control systems for toroidal magnetic field as well vertical are added, rf wave injection sustaining plasmas upgraded. After modification, device now can work not only a tokomak pulsed plasma currents it was but also simple magnetized torus discharges. It allows more flexible efficient experimental researches on magnetically confined to be carried same
A supersonic molecular beam injection (SMBI) system was developed on the J-TEXT tokamak. With SMBI fueling, a continuous electron density increase successfully achieved when multiple-pulse employed. steeper profile observed during penetration process. high fueling efficiency, between 20% and 45%, obtained in limiter/ohmic discharges, suggesting that is superior method. efficiency decreased with increasing background density. Analyses of process H <sub...
The electron cyclotron resonance heating (ECRH) system with a 60 GHz/200 kW/0.5 s gyrotron donated by the Culham Science Center is being developed on J-TEXT tokamak for plasma heating, current drive and MHD studies. Simultaneously, an anode power supply (APS) has been rebuilt tested output control of gyrotron, which input voltage derived from 80 kV negative cathode supply. strategy controlling grid tetrode TH5186 applied to obtain accurate climbing voltage, can be obtained 0–30 respect...
Abstract Power measurement is necessary for an electron cyclotron resonance heating (ECRH) system. The directional coupler method has been put forward to monitor high-power microwave from gyrotrons in real time. A multi-hole designed and manufactured the 105 GHz/500 kW ECRH system on J-TEXT tokamak. During design process, we established relationships between hole parameters coupling characteristics based small-hole theory. High-power tests have carried out. results indicated reasonability of...
Abstract As a promising method for fast ion diagnostics, collective Thomson scattering (CTS) can measure the one-dimensional velocity distribution of ions with high spatial and temporal resolution. The feasibility diagnosing in compact high-field tokamak by CTS was studied this work, results showed that wide range probing frequencies could be applied. A high-frequency case low-frequency were mainly considered diagnostics tokamak. use frequency effectively avoid refraction effect beams, while...
The absorption spectra of ZnSe-ZnS strained-layer superlattices were measured at temperatures ranging from 16 K to room temperature. Three excitonic peaks corresponding 1E-1HH, 1E-1LH, and 1E-3HH transitions observed for the first time.
Time and space resolved measurements of the radial electric field (Er) have been conducted during electrode biasing experiments on KT-5C tokamak. The suppression turbulent transport with change Er induced by biased is observed. It found that poloidal flow contributes to main part Er, has a lead about 20 µs formation Er. These observations suggest current, responding an voltage electrode, drives which in turn field.
To improve the understanding of turbulence intermittency, a detailed investigation intermittency density fluctuations has been performed in boundary J-TEXT. The and its influence on radial transport are reported. probability distribution functions not scale-invariant, being inconsistent with self-organized criticality hypothesis. underlying dynamics detected using quiet-time statistical method. function quiet times shows double-power-law regions, indicating existence correlations between...